Surface heating unit construction



Jan. 9, 1962 e. LlEN, JR 3,016,445

SURFACE HEATING UNIT CONSTRUCTION Filed Nov. 20, 1959 2 Sheets-Sheet 1Fig I 26 O O 63 74 Q Q I 5! 31.3 44 28 30.! 26 56 I 7.! 5 65 46 I9 I.!Flq. 2 Q 58 60 57 I92 37.3

INVENTOR. GUNDER LIEN,JR. BY

ATTY

Jan. 9, 1962 G. LIEN, JR 3,016,445

' SURFACE HEATING UNIT CONSTRUCTION Filed Nov. 20, 1959 2 Sheets-Sheet 2INVENTOR. GUNDER LIEN, JR,

ATTY.

' nite The present invention relates to electric surface cooking unitsand more particularly to hinging mechanisms for the same.

It is a principal object of the invention to provide an improved hingeconstruction which will position the cooking unit in an operative manneron the cooking surface and which will permit the unit to be swung upwardto a stable raised position at which the cooking unit may be completelyremoved.

It is another object of the invention to provide an improved hingemechanism which latches the hinge mechanism in the raised position sothat the cooking unit or as it may be called, a heating unit, may beremoved from the hinge, after which the hinge remains in its unitreceptive position to facilitate replacement of the unit on the hinge.

It is a further object of the invention to provide a support structurefor the cooking unit heating coils from which the heating coils may bereadily demounted.

In the embodiment described herein, there is a spring hinge mechanismaffixed internally to the cooking surface adjacent to the periphery ofthe heating coil cutout. The hinge mechanism has as its main operativemember a generally L-shaped hinge bracket pivoted near the outer tip ofthe short leg of the L. At the outermost end of the short leg of the Lis a crowned tip co-operating with a retaining spring for holding thehinge arm in one of two desired positions. The long section of the L. isremovably inserted through suitable slots in a support bracket mountedto the underside of the heating coil support structure. By thisconstruction the heating coil may be tilted about the hinge arm pivotfrom the operative horizontal position to a raised position; a crownedtip of the L bracket short leg being resiliently engaged to hold thehinge firmly in the raised position. By siding the heating unit up theplane of the hinge arm in the raised position, the heating unit may bewithdrawn from the hinge arm and removed for cleaning or replacement asrequired.

The invention further comprises a trim ring surrounding the heatingcoils and detachably mounted to the heating unit support structure. Thedetachable feature is achieved by having the trim ring vertical sidewallformed with two diametrically opposed inwardly directed embosses.Displaced angular'y from the embosses are two slots arranged in opposedsections of the sidewall. One of the slots is backed by a resilient fiatspring. The heat coil support structure embodies angularly disposed armsadapted to rest on an emboss, an additionally a second set of arms, thetips of which are designed to fit into the sidewall slots. One of thesetips is contacted by the flat spring and the arm is retained in place.By manual pressure on the arm against the bias-the flat spring, theopposing tip may be displaced out of its slot releasing the trim ring.The reverse of this operation is performed on re-assembly of the coilstructure and trim ring.

, The invention both as to its organization and principle of operation,together with further objects and advantages thereof, will best beunderstood by reference to the following specification taken inconnection with the accompanying drawings in which:

FIG. 1 is a fragmentary top plan View of an electric range and cookingunit with portions of the range cooking top broken away, and portions ofthe cooking unit in section;

atent 3,hlh,445

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FIG. 2 is a vertical section taken along the lines 2-2 of FIG. 1;

FIG. 3 is a vertical sectioned side elevation of the hinge elementshowing the unit in raised position.

FIG. 4 is also a vertical sectioned side elevation of the hinge elementshowing the unit in the raised position with the unit partially removedfrom the hinge.

FIG. 5 is a top plan view of the support structure and trim ring withthe heating coil removed.

FIG. 6 is a fragmentary sectional view taken along the line 66 of FIG.5. i

In the typical installation, the heating units are mounted in aconventional electric range having a cooking top 11 provided with asuitable number of circular openings 12, each adapted to receive acooking unit 13. Usually there are three or four of such cooking unitssuitably arranged about the cooking top.

Each cooking unit generally comprises a first sheathed heating element14 having respective terminal portions 15 and 16 and a second sheathedheating element 17 having the terminal portions 18 and 19. Preferably,these elements will be constructed as described in the United StatesPatent to C. C. Abbott, No. 1,367,341 dated February 1, 1921, and in theJ. C. Sharp Reissue Patent No. 22,177 of September 8, 1942. Each ofthese elements, as described in the cited patents, has a coiledresistance conductor housed in a metallic sheath and supported inuniformly spaced relationship to the sheath by a highly compacted massof a suitable heat conducting and electrically insulating material suchas powdered magnesium oxide. As is conventiona the heating elements arearranged to form fiat spirals of several convolutions and are nested onewithin the other on a carriage structure which may include a pluralityof radially extending vertically arranged plates 24, 25, and 26 joinedtogether at a central hub and extending radially therefrom. The upperedges of these plates lie in a common plane and support the heatingelements as shown.

The support structure is carried by a trim ring having a horizontal rim27 resting on the cooking top 11 about the opening therein and adownwardly extending circular sidewall flange 28 which is spacedinwardly from the depending flange 29 defining the cooking top opening12. An advantageous manner of securing the support structure to the trimring is by providing certain of the support plates with a short tongue34 brought through a suitable slot in the trim ring wall 28 as will beexplained more fully later in this specification. The trim ring thusestablishes the plane of the upper edges of the support plates parallelto the plane of the cooking top 11. A suitable drip and reflector pan(not shown) may be removably supported below the heating unit asrequired.

The respective heating elements rest on the upper edges of the radialsupport plates, and each element is secured to only one of the plates atonly one point. As shown in H6. 2, an outer convolution of each of theheating elements is anchored to the support plate 25 by means ofupwardly extending pairs of jaws which grip the sheath of the respectiveheating elements. Except for this single point of attachment of theheating elements to the support structure, the elements are free to moveon the upper edges of the supporting structure as they expand andcontract with temperature changes. The terminal portions of the heatingelements extend downwardly from the support plates and rectilinearlybeneath the cooking top 11 and have conductor terminals 15.1, 16.1,18.1, and 19.1 extending therefrom. T hese conductor terminals may havewelded thereto rivets such as 19.2 shown in FIGS. 2, 3, and 4 ofsuitable contact material, i.e. nickel silver.

In order to form a connection from these terminals 3,01e,aas

to a conventional source of 230 volt, 3 conductor power, a terminalblock 33 preferably of molded vitreous refractory material is mountedstationarily in any known manner to the underside of the cooking top 11adjacent the cooking top-cutout 12. The terminal block has a solid upperhalf 34 and four terminal receiving channels 35, 36, 37, and 38 in itslower half, each channel being adapted to receive respective terminalends 15.1, 18.1, 19.1, and 16.1. The channels are separated by suitableinternal walls which tend to electrically insulate each channel from theadjacent channel. Each of the channels has an upstanding rear wall 35.1,36.1, 37.1, and 38.1. Each rear wall at its lower end terminates in anangled 7 section such as 37.2 of channel 37. Each of the angled sectionshas secured therein a single resilient blade contactor such as 37.3which extends freely upwardly into the channel for the purpose ofengaging the proper terminal end such as 19.1. To provide the severallevels of thermal output normally required, a bus-bar (not shown) couldbe provided between adjacent contactors such as between 35.3and 36.3 orbetween 37.3 and 38.3. Utilizing this latter alternative for example, anelectrical circuit would be completed from the first source lead throughcontac'tor 38.3, the conductor of terminal end 16.1, heating element 14,and terminal end 15.1 to contactor 35.3 and the second source lead. Aparallel circuit would also be completed from contactor 38.3 tocontactor 37.3 and through the conductor of terminal end 19.1, heatingelement 17 and terminal end 18.1, and contactor 36.3 to the third sourcelead.

Referring more particularly to FIGS. 2, 3 and 4, there is shown ahinging and grounding structure which embodies the present invention.The structure has as its main components, a hinge strap 40 secured tothe cooking top, a pivotable hinge arm 41 and a hinge arm receivingmember 42 secured to the support structure. The hinge strap 40 comprisesa rigid base plate 44 from which extend upwardly both a pivot plate 45and a rigid attachthem strap 46 which strap is arranged to be mountedflush against the flange 29 around the cooking top opening. The strap issecured to the range frame at the cooking top opening by means of aself-tapping screw 47 or equivalent which secures the attachment strap46 firmly against the opening flange 29.

Toward the upper end of pivot plate is secured a hinge pin 48 aboutwhich the heating unit hinge arm 41 is pivoted. Hinge arm 41 comprises asubstantially L- shaped member, with the hinge pin 48 adjacent the endof the short leg 41.1. At the outer tip of the leg 41.1 is a crownedportion 50 which nests within a resilient recurved section 51 of hingestrap 40 to firmly hold the hinge arm in position. The longer leg of theL-shaped hinge arm terminates in a blade-like extension 52 which whenthe heating unit is in normal operating position is substantiallyparallel to the cooking top and the plane established by the heatingelement convolutions. This blade-like extension 52 is designed to fit,bayonet arm fashion, through slots 55 and 56 respectively aligned inlegs 57 and 58 of the inverted U-shaped, arm-receiving frame member 42which is part of the heating unit supporting structure or carriage. Thelegs 57 and 58 depend from the base of the U member and are alignednormal to the plane described'by the hinge blade extension 52. The bladeextension 52 is latched firmly within the slots by virtue of itsenlarged shoulder sections 60 and 61 which abut leg 57 and a headsection 62 which project s through slot 56 with the sloping head sectionlatching surface 62.1 abutting leg 58. Affixed within the base of the Umember 42 is a formed-over grounding spring 63 which tends to bias theblade extension by downward pressure along its upper surface thusyieldably maintaining the latched relationship between the member 42 andblade extension 52. Member 42 has extending upwardly om its invertedbase a support arm 64 which is per- ;anently affixed to support plate 24of the heating element which are crimped about the sheaths of adjacentterminals 16 and 19. It should be noted that collars 65 and 66 are bothintegral to leg 57 and that the other leg, 58, also surrounds terminals16 and 19 to form a more solid structure.

In all such range applications where high voltages are to be impressedupon the conductors of the sheathed heating element, it is necessarythat the heating element sheathing be grounded to the cooking top. Inthe hinge mechanism as previously described, a ground path can be tracedfrom the heating element sheaths, through the collars 65 and 66,grounding spring 63, inverted U member 42,

pivotable hinge arm 41, hinge strap 46 and its attachment strap 46 tothe cooking top metal surface at self-tapping screw 47.

The advantages of the present embodiment may be most readily appreciatedby a description of the co-operation of the components as the heatingunit is moved from the normal position described previously to theraised position and the detached position. The heating element may betilted from its operative position to the raised position of FIG. 3, bymanually lifting on the outer end of the trim ring. The firm connectionof the inverted.

support member 42 to the mating blade extension 52 causes the L-shapedhinge arm 41 to follow and pivot about hinge pin 48. The travel of thehinge arm 41 is stopped by engagement with the lower portion ofdepending cooking top flange 29. At the time this occurs, crowned tip 50nests in offset 51.1 of the hinge strap recurved section 51 toresiliently hold the hinge arm and the heating element in the raisedposition. As the heating element is tilted, it can be seen that theterminal ends will rotate away from their matching contactors and thuswill be freed of the terminal block area. It should be noted that afterthe terminal ends are freed of the contactors, the grounding of thesheath remains completed. With the heating element in the raisedposition, the heating element may be removed from the hinge by firmlygrasping the heating element and pulling the heating eleent up the planeestablished; spring 63 is thereby compressed freeing the interferencecontact of head section 62 of the hinge arm from the abutting U memberleg 58. The heating element may then be removed as the blade extensionmay slide freely within slots 55 and 56. With the heating elementremoved, the hinge arm is positively retained in a position receptive tothe return of the heating element by the previously described nesting ofthe hinge arm crowned tip 50 in the offset 51.1. The heating elernentmaythen be returned to the hinge by an obvious reversal of the steps listedfor the-removal.

A further feature of the present embodiment lies in the removability ofthe trim ring from the support structure as may most readily be seeninFIGS. 5 and 6. For the sake of simplicity in FIGS. 5 and 6, the heatingelement has been shown removed, although in actuality this would not bethe case. As can be seen, the depending flange 28 of the trim ring hasopposed embosses 70 and 71 formed inwardly near the bottom edge of theWall. Spaced 90 from these embosses are opposed slots 73 and 74 in thetrim ring side wall 28. Outwardly of slot 74, there is secured to thetrim ring sidewall a spring member 75 which isbiased toward the sidewall28. To

fit within the trim ring as described, the support structure is formedgenerally in the shape of an arrow with plate 24 acting as the centralshaft of the arrow. Central plate 24 of the support structure has itsopposite ends formed with tongues 30 and 30.1 designed to fit intoopposed slots 73 and 74. The side plates 25 and 26 are formed generallyinto 'V shapes, each. of the bases of Split/lad which are shaped toconform and rest upon the opposed embosses 70 and 71.

To remove the trim ring, radial pressure would be exerted along plate 24against the bias of leaf spring 75 to allow tongue 30.1 to be freed ofslot 73. By then raising this end of plate 24, the V bases can be raisedoff their mating embosses and tongue 30 may then be freed of slot 74.

By the invention shown, the entire heating element can be removed fromthe cooking top for cleaning and further the trim ring may be removedfrom the support structure and heating element for further ease ofcleaning of the components individually.

While there has been described what is at present considered to be thepreferred embodiment of the invention, it will be understood thatvarious modifications may be made therein, and it is intended to coverin the appended claims all such modifications as fall within the truespirit and scope of the invention.

What is claimed is:

1. A heating unit adapted to be mounted in the top surface of a rangeand comprising a heating element and a carriage structure for supportingsaid element in an operative position parallel to said top surface, ahinge member engaging said heating element carriage structure forretaining said unit in said operative position, means for resilientlyholding said hinge member in a second position oblique to said surfaceto thereby maintain said heating unit in an inoperative position obliqueto said surface, means for normally retaining said hinge memberin'engagement with said carriage structure, and means responsive toupward movement of said heating unit with respect to said hinge memberto release the engagement of said heating element carriage structure andsaid hinge member, said holding means thereafter maintaining said hingemember in said second position receptive to the return of said heatingunit.

2. A heating unit adapted to be mounted in the top surface of a rangeand comprising a heating element and a carriage structure for supportingsaid element in an operative position parallel to said top surface, ahinge member affixed to said surface and releasably secured to saidstructure to allow rotation of said unit from said operative position toa second inoperative position angled from said surface, means forholding said hinge member in said second position, and means forreleasably retaining said hinge member engaged to said carriagestructure, said releasable retaining means including a resilient membercapable of yielding to upward movement of said heating unit along theplane established by said heating unit in said second position forreleasing said engagement to allow slide action detachment of saidheating unit from said hinge member, said holding means thereafterrestraining said hinge member in said second position receptive to theslide action return of said heating unit to said hinge member.

3. A heating unit adapted to be mounted in the top surface of a rangeand comprising a heating element and structure for supporting saidelement in an operative position parallel to said top surface, a hingemember affixed to said surface and including a bayonet arm, saidstructure including a depending frame encircling said bayonet arm forretaining said unit in said operative position, means for holding saidbayonet arm in a second position oblique to said surface to therebymaintain said heating unit in an inoperative position, and means forreleasably retaining said frame encirclement of said bayonet arm therebyretaining said hinge member engaged to said structure, said releasableretaining means comprising a resilient member biasing said bayonet armwithin said depending frame, said resilient member yielding to upwardmovement of said heating unit oblique to said surface for releasing saidbias to allow removal of said heating unit from said hinge member, saidholding means thereafter operative to hold said bayonet arm in saidsecond position receptive to the return of said frame to said arm.

4. In an electric range having a structure providing a cooking surfaceformed with an opening for the reception of a cooking unit in anoperative. position substantially parallel to said cooking surface; saidcooking unit cornprising a support structure, a flat heating coilresting on said support structure, a plurality of rigid terminalsextending from said coil; means for providing a source of current forsaid unit comprising a stationary terminal box aihxed to said cookingsurface for receiving said terminals to maintain electrical contact withsaid cooking unit in the operative position; hinge means secured to saidcooking surface adjacent said opening for controlling the movement ofsaid cooking unit from said operative position to an inoperativeposition oblique to said cooking surface,

said hinge means comprising a latch blade member engaging said sup-portstructure for governing the movement thereof, spring means engaging saidlatch member for retaining said latch blade in a first position parallelto said cooking surface for thereby maintaining said cooking unit insaid operative position, said spring means further being effective toretain said latch blade in a second position oblique to said cookingsurface for maintaining said cooking unit in said inoperative positionwith said terminals out of contact with terminal box; a bifurcatedcarriage depending from said support structure normal to said cookingsurface, said carriage having fork portions encircling certain ones ofsaid terminal extensions, said fork portions having aligned slots forreceiving said latch blade, bias means for releasably retaining saidlatch blade in said slots, said bias means being responsive to pressureexerted along the plane of said blade with said latch blade in saidoblique position to release said latch blade from said carriage therebyallowing said cooking unit to be removed from said cooking surface andhinge means.

5. In an electric range having a structure providing a cooking surfaceformed with an opening for the reception of a c oking unit in anoperative position substantially parallel to said cooking surface; saidcooking unit comprising a support structure bridging said opening, afiat heating coil resting on said support structure and a plurality ofrigid terminals extending from said coil; the combination comprising astationary terminal member affixed to said coo-king surface and having aplurality of individual contacts for receiving said terminals inelectrical contact with said cooking unit in the operative position;hinge means secured to said cooking surface adjacent said opening forcontrolling the movement of said cook ing unit from said operativeposition to an inoperative position oblique to said cooking surface inwhich said terminals are disengaged from said contacts, said hinge meanscomprising an L-shaped member engaging said support structure forgoverning the movement thereof, spring means engaging the shorter arm ofsaid L-sbaped member thereby retaining the longer arm of said L-shapedmember in a first position parallel to said cooking surface thusmaintaining said cooking unit in its operative position with theterminals contacting said individual contacts, said spring means alsoengaging the shorter arm for retaining the longer arm of said L-shapedmember in a second position oblique to said cooking surface thusmaintaining said cooking unit in said inoperative position; a carriagestructure depending from said support structure normal to the longer armof said L-shaped member, said carriage structure having rigid membersengaging certain ones of said terminal extensions in axially spacedrelation, said rigid members having means for receiving said longer arm,and means including a biasing member for releasably retaining saidlonger arm in said receiving means, said biasing member yielding toeffort exerted along the plane of said longer arm with said L-shapedmember in said second position to release said longer arm fordisengagement 7 from said carriage structure, thereby allowing saidheating coil to be removed from said cooking surface.

6. In an electric range having a structure providing a cooking surfaceformed With an opening for the reception of a cooking unit in anoperative position substantially parallel to said cooking surface; acooking unit comprising a support structure bridging said opening, aflat heat ing coil resting on said support structure, a plurality ofrigid terminals extending from said coil, a stationary terminal boxafiixed to said cooking surface for releasably receiving said terminalsin electrical contact with said cooking unit in the operative position,hinge means secured to said cooking surface adjacent said opening forcontrolling the movement of said cooking unit from said operativeposition (to a raised inoperative position, said hinge means comprisingan angled member engaging said support structure for governing themovement thereof, spring means operative for retaining one leg of saidangled member in a first position parallel to said cooking surface thusmaintaining said cooking unit in said operative position and forretaining said one leg of said angled member in a second positionoblique to said cooking surface thereby maintaining said cooking unit insaid inoperative position, a carriage structure depending from andsecured to said support structure normal to said one leg of said angledmember and means on said carriage structure for releasably receivingsaid one leg, whereby said cooking unit may be separated from said hingemeans leg for removal of said cooking unit from said cooking surface,with the said spring means retaining said hinge means with the said oneleg thereof in an angular position receptive to the return of saidcooking unit thereon.

7. An electric cooking range, comprising structure providing ahorizontal cooking surface having an opening, an electric heating unit,combination hinging and release means for supporting said heating unitin anoperative position within said opening or in an inoperativeposition in raised angular relation to said cooking top, saidcombination hinging and release means including a hinge structure fixedto said range structure adjacent to said surface opening, a hinge memberextending substantially diametrically into said opening, carriage meansfor said heating unit, including means for mounting said carriage meanson said hinge member for slidable withdrawal therefrom, latch meansco-op-erating between said hinge memher and said carriage means, andresilient means interfaced between said carriage means and said hingememher for normally maintaining the same in engaged relationship whileyielding to a direct withdrawal of said carriage means from said hingemember following angular displacement of said heating unit relative tosaid cooking surface.

8. An electric cooking range, comprising structure providing ahorizontal cooking surface, an electric heating unit, and means forhingedly supporting said heating unit on said structure for movementbetween a horizontal operatingp'osition and an angular inoperativeposition,

- blade-like member, means establishing a latching connection betweensaid carriage means and said blade-like member, spring means yieldablymaintaining said latching connection to permit desired angulardisplacement of said heating unit relative to said' cooking surfaceWhile permitting withdrawal of said carriage means from said hingemember, and means for maintaining said hinge member in a positionreceptive to the return of said carriage means to said hinge member.

9. A heating unit adapted to be mounted in a cooking top surface andcomprising a coiled heating element and a carriage structure joinedthereto for supporting said element in an operative position parallel tosaid top surface, means for hinging said heating element for movementbe-v tween a first position parallel to said top surface and aninoperative position oblique to said top surface, terminal I membersextending in stepped fashion from said element to connect said heatingelement to a source of electric power, a stationary terminal blockdepending from said top surface, means in nals with said heating elementin said first position for completing the connection of said terminalsto, said power source, said circuit completing means, opening saidconnection to said power source with the heating element in said secondposition, means for detachably locking said heating element to saidhinging means to allow ready removal of said heating element from saidhinging means, and means for latching said hinging means in said secondposition receptively poised for return of the heating element thereto.

References (Cited in the file of this patent UNITED STATES PATENTS saidblock receptive to said termi- I V

